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Related papers: Quantum nonlocality of four-qubit entangled states

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We study the relation between violation of Bell inequalities and distillability properties of quantum states. Recently, D\"ur has shown that there are some multiparticle bound entangled states, non-separable and non-distillable, that…

Quantum Physics · Physics 2009-11-07 A. Acin

To date, most efforts to demonstrate quantum nonlocality have concentrated on systems of two (or very few) particles. It is however difficult in many experiments to address individual particles, making it hard to highlight the presence of…

Entanglement and violation of Bell inequalities are aspects of quantum nonlocality that have been often confused in the past. It is now known that this equivalence is only true for pure states. Even though almost all the studies of quantum…

Quantum Physics · Physics 2012-06-01 L. Justino , Thiago R. de Oliveira

We examine the two-party perfect quantum teleportation of an unknown 1-qubit state in the case of sharing various 3-qubit entangled states between a sender and a receiver: GHZ state, W state and W-like state. We give an impossibility proof…

Quantum Physics · Physics 2026-04-03 Sora Kobayashi , Kei-Ichi Kondo

We explore the relationship between Kochen-Specker quantum contextuality and Bell-nonclassicality for ensembles of two-qubit pure states. We present a comparative analysis showing that the violation of a noncontextuality inequality on a…

Quantum Physics · Physics 2024-02-26 Giovanni Scala , Antonio Mandarino

The states in the three-qubit GHZ SLOCC class can exhibit diverse entanglement patterns, as they may have no entanglement in any reduced subsystems, or show entanglement across one, two, or all three bipartite cuts. Significant research has…

Incompatibility and nonlocality are not only of foundational interest but also act as important resources for quantum information theory. In the Clauser-Horne-Shimony-Holt (CHSH) scenario, the incompatibility of a pair of observables is…

Quantum Physics · Physics 2023-02-21 Swati Kumari , Javid Naikoo , Sibasish Ghosh , A. K. Pan

The violation of the Svetlichny's inequality (SI) [Phys. Rev. D, 35, 3066 (1987)] is sufficient but not necessary for genuine tripartite nonlocal correlations. Here we quantify the relationship between tripartite entanglement and the…

Quantum Physics · Physics 2010-11-16 Ashok Ajoy , Pranaw Rungta

According to quantum theory, the outcomes obtained by measuring an entangled state necessarily exhibit some randomness if they violate a Bell inequality. In particular, a maximal violation of the CHSH inequality guarantees that 1.23 bits of…

Quantum Physics · Physics 2012-03-23 Antonio Acin , Serge Massar , Stefano Pironio

Local measurements on bipartite maximally entangled states can yield correlations that are maximally nonlocal, monogamous, and associated to fully random outcomes. This makes these states ideal for bipartite cryptographic tasks.…

Quantum Physics · Physics 2015-05-30 Leandro Aolita , Rodrigo Gallego , Adán Cabello , Antonio Acín

We propose a way for generating $n$-qubit Greenberger-Horne-Zeilinger (GHZ) entangled states with a three-level qubit system and (n-1) four-level qubit systems in a cavity. This proposal does not require identical qubit-cavity coupling…

Quantum Physics · Physics 2015-05-28 Chui-Ping Yang

We analyze a possibility of using the two qubit output state from Buzek-Hillery quantum copying machine (not necessarily universal quantum cloning machine) as a teleportation channel. We show that there is a range of values of the machine…

Quantum Physics · Physics 2008-10-01 S. Adhikari , N. Ganguly , Indranil Chakrabarty , B. S. Choudhury

High dimensional quantum entanglement and the advancements in their experimental realization provide a playground for fundamental research and eventually lead to quantum technological developments. The Horodecki criterion determines whether…

Quantum Physics · Physics 2025-04-29 Swapnil Bhowmick , Som Kanjilal , A. K. Pan , Souradeep Sasmal

It is a well-established fact that some quantum correlations can be nonlocal, meaning that they cannot be described by a local hidden variable model. Certain quantum correlations have a form of nonlocality so strong that they cannot be…

Quantum Physics · Physics 2026-04-30 Martin J. Renner , Edwin Peter Lobo , Arturo Konderak , Remigiusz Augusiak , Antonio Acín

Multipartite entangled states are great resources for quantum networks. In this work we study the distribution, or routing, of entangled states over fixed, but arbitrary, physical networks. Our simplified model represents each use of a…

Quantum Physics · Physics 2019-12-04 Clément Meignant , Damian Markham , Frédéric Grosshans

The existence of correlations between the parts of a quantum system on the one hand, and entanglement between them on the other, are different properties. Yet, one intuitively would identify strong $N$-party correlations with $N$-party…

Quantum Physics · Physics 2020-02-12 Christopher Eltschka , Jens Siewert

Quantum entanglement and quantum nonlocality of $N$-photon entangled states $|\psi_{N m}> =\mathcal{N}_{m}[\cos\gamma|N-m>_{1}|m>_{2} +e^{i\theta_{m}}\sin\gamma|m>_{1}|N-m>_{2}]$ and their superpositions are studied. We indicate that the…

Quantum Physics · Physics 2009-11-11 Yan-Hua Sun , Le-Man Kuang

We present a set of Bell inequalities that gives rise to a finer classification of the entanglement for tripartite systems. These inequalities distinguish three possible bi-separable entanglements for three-qubit states. The three Bell…

Quantum Physics · Physics 2007-05-23 Bao-Zhi Sun , Shao-Ming Fei

States that strongly violate Bell's inequalities are required in many quantum informational protocols as, for example, in cryptography, secret sharing and the reduction of communication complexity. We investigate families of such states…

For two qubits in a pure state there exists a one-to-one relation between the entanglement measure (the concurrence ${\cal C}$) and the maximal violation ${\cal M}$ of a Bell inequality. No such relation exists for the three-qubit analogue…

Quantum Physics · Physics 2007-05-23 C. Emary , C. W. J. Beenakker
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